visual_debugger/cpp/main.cpp

#include <iostream>
#include <optional>

// A single node containing data and a raw pointer to the next node
template <typename T>
struct Node {
    T data;
    Node<T>* next;
};

// The main wrapper for the linked list tracking the head node
template <typename T>
class LinkedList {
public:
    LinkedList() : head_(nullptr) {}

    ~LinkedList() {
        Node<T>* current = head_;
        while (current) {
            Node<T>* next = current->next;
            delete current;
            current = next;
        }
    }

    // Raw-pointer ownership can't be safely duplicated by a shallow copy
    LinkedList(const LinkedList&) = delete;
    LinkedList& operator=(const LinkedList&) = delete;

    // Add a new element to the front of the list
    void push_front(T data) {
        head_ = new Node<T>{std::move(data), head_};
    }

    // Remove and return the front element of the list
    std::optional<T> pop_front() {
        if (!head_) {
            return std::nullopt;
        }
        Node<T>* old_head = head_;
        T data = std::move(old_head->data);
        head_ = old_head->next;
        delete old_head;
        return data;
    }

    // Read the front element without removing it
    const T* peek_front() const {
        return head_ ? &head_->data : nullptr;
    }

private:
    Node<T>* head_;
};

int main() {
    LinkedList<int> list;
    int count=0;
    char * message1 = "hello world";
    // Demonstrate pushing items
    list.push_front(10);
    count++;
    list.push_front(20);
    count++;
    list.push_front(30);
    count++;

    // Demonstrate peeking at the top item
    if (const int* top = list.peek_front()) {
        std::cout << "Top element: " << *top << "\n"<<"count: "<<count<<"\n"; // Output: 30
    }
    std::cout<<message1<<"\n";

    // Demonstrate popping items
    while (auto value = list.pop_front()) {
        std::cout << "Popped: " << *value << "\n";
    }

    return 0;
}